HIGH-TEMPERATURE STUDIES OF METALLURGICAL PROCESSES: PART I. THE THERMAL REDUCTION OF MAGNESIUM OXIDE WITH SILICON

Abstract

The rate of reaction (a) has been studied over the temperature range 1140–1460 °C, by following the loss in weight of the reactants in high vacuum.[Formula: see text]The loss in weight of the reactants was found to be greater than that which can be accounted for by the above reaction. The excess weight loss was found to be due to a brownish, glassy deposit which appeared outside the reaction zone. This material was analyzed by X-ray diffraction and found to be an intimate mixture of Mg2SiO4 and Si. Experiments conducted showed that both of these materials are not appreciably volatile at 1350 °C. This transfer of silicon and silicate is postulated to occur by the formation of gaseous SiO formed from the reaction mixture. Based on this assumption a possible mechanism for this reaction is postulated.